The present invention relates to receivers for television signals and, more particularly, to a television signal receiver capable of selecting a television standard appropriate for use in a particular television standard region.
There are a number of different types of television broadcasting systems or standards used throughout the world, such as PAL, SECAM, and NTSC. The various standards have different features and/or peculiarities that make them incompatible relative to each other. Because of the differences between the various standards, it is not possible to receive and/or view television signals on a television receiver that processes a standard which is different from the standard of the received television signals. Fortunately, a particular standard is used throughout a particular region or area. As such, televisions are typically manufactured for a particular region and thus include processing circuitry only for the particular television signal standard for that region.
In view of the above, televisions have been developed that are able to receive and process television signals of different standards, for example, see U.S. Pat. Nos. 4,309,719 entitled xe2x80x9cDual Standard PAUSECAM Receiver Circuitryxe2x80x9d; 4,414,563 entitled xe2x80x9ctelevision Receiver Circuit Arrangement for Identifying the Standardxe2x80x9d; 4,688,082 entitled xe2x80x9cMulti-System Television Receiverxe2x80x9d; and 5,267,024 entitled xe2x80x9cMultiple Systems Adaptive Television Receiverxe2x80x9d. However, in each case, the prior art utilizes parameters of the received television signal to select and change the processing from one television signal standard to another television signal standard.
One difference between the various television standards is the number of horizontal scan lines. Since the number of horizontal scan lines is different for each standard, it is usually not possible to select the appropriate television standard by an on-screen display (OSD) feature or a menu structure since a mismatch between the signal standard of the outputted television signal and the signal standard processing mode of the television can prevent a readable display from being shown on the television.
With respect to television signals emanating from a satellite, the satellite television signals are typically digital (i.e. digitally modulated analog signals) and thus are not encoded with respect to any particular television signal standard.
In view of the above, it is desirable to have a television signal receiver that is capable of automatically determining the television standard in use at a particular location.
The present invention is a television signal receiver operable to receive and process a television signal and output the television signal in one of a plurality of television signal standards or formats corresponding to a local television standard. The television signal receiver utilizes a parameter of the electricity supplied (coupled to) the television signal receiver in order to aid in the determination of which television signal standard to use for processing/modulating the received television signal.
In one form, the television signal receiver is a satellite receiver operable to receive satellite broadcast television signals and convert the television signals into the NTSC or PAL standard depending on the local preference. A frequency/period or voltage characteristics (parameters) of the electricity supply for the satellite receiver is ascertained and used in order to make a determination as to which television standard to use for processing/modulating and outputting the television signal.
In a case where there may be more than one frequency/period of electricity or power in use at a particular location, a supplemental determinator of standards may be used in conjunction with the use of electricity parameters. The supplemental determinator may be an on-screen display (OSD) that allows a user to choose between similar standards when the exact standard cannot be determined from the power-line (electricity) parameters.
The OSD may be displayed when particular characteristics of the electricity are initially determined. This typically occurs in an area where different voltages and/or frequencies are available or in use. When this occurs, the television standard that is utilized is similar to the television standard that is not utilized (e.g. NTSC and PAL-M). Therefore the OSD may be displayable.
In another form, the present invention is a television signal processing apparatus. The television signal processing apparatus includes a plurality of video signal processing paths or circuitry each of which provides television signal processing according to a respective one of a plurality of television signal standards. Means for determining a parameter (e.g. frequency or voltage characteristics) of a source of electrical operating power of the television signal processing apparatus is provided. Means for generating a control signal representative of the parameter of the source of electrical operating power of the television signal processing apparatus is also provided. The television signal processing apparatus further includes means responsive to the control signal for selecting one of the plurality of video signal processing paths for processing of an input television signal.
In yet another form, the present invention is a television signal processing apparatus that includes processing circuitry configured to receive a television signal, a modulator in communication with the processing unit and configured to provide television signal processing of the received television signal according to a respective one of a plurality of television standards, and electricity parameter determination circuitry in communication with a source of AC electricity and configured to provide a first signal to the processing circuitry indicative of a parameter of the supplied AC electricity. The processing circuitry is configured to provide a control signal to the modulator for selecting a particular one of the plurality of television standards in accordance with the first signal.
In still another form, the present invention is a method for processing a television signal input to a television signal processing apparatus. The method includes the steps of: a) determining a parameter of a supply of AC operating power of the television signal processing apparatus; b) generating a control signal corresponding to a parameter of the source of AC operating power of the television signal processing apparatus; and c) selecting one of a plurality of video signal processing paths for processing the input television signal in response to the control signal with each of the plurality of video signal processing paths providing television signal processing according to a respective one of a plurality of television signal standards.